My system suspended, but did not resume. How can I figure out why?
Resume debugging can be quite a bit trickier, as the failure could well have occured before the machine is actually suspended, or in low level startup code where debugging can be quite difficult. So lets look at two common scenarios:
My machine will not power on after pressing a key or the button.
The common reason is that the keyboard or button hardware was not configured to wake the machine. This can be as simple as a setting in the machines BIOS to specify what evens can wake the machine. It might also be that the keyboard (likely USB, but could be PS2) or button drivers inadvertently or even purposely disabled the wakeup generation.
So first check to see if there is an option in the BIOS's power management section for enabling wakeups. You might even see if the BIOS supports Wake on LAN, enable the network controller for WOL, and see if a Magic Packet can wake the machine.
If still no joy, identify what the driver hierarchy for the keyboard is, and submit questions or bugs to those sets of individuals as well as <mailto:pm-discuss@opensolaris.org> for further help.
My machine powers on, but does not fully wake.
This is likely due to a driver that failed to resume. Unfortunately, drivers that fail DDI_RESUME will always kill the machine, as driver failures at this point are usually fatal. Hopefully, though, the root disk drive was resumed, and a log was written as to the failing device. If this is a reproducible problem, boot via kmdb, and see if it will show a failure point. Otherwise, check to see if the log shows any "Failed to resume" messages, and lookup this driver in /etc/driver_aliases. Again, file bugs where appropriate.
If still there is a problem, you will need more help from <mailto:pm-discuss@opensolaris.org>.